Berlin climate

Berlin Frost Dates and Growing Season

NOAA 1991-2020 normals for Berlin, 1.7 km from Berlin, elevation 920 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Berlin. A median date has an even chance of a later freeze in spring, or an earlier one in fall.

The last spring freeze typically comes around May 14 and the first fall freeze around September 30, a growing season of about 135 days.

Median at 36°F
last May 29, first September 18
Median at 32°F
last May 14, first September 30
Median at 28°F
last April 30, first October 10

Last freeze in spring

The chance of a later freeze than the date shown. At 10 percent, one spring in ten still freezes after the date; planting after the 10 percent date for 32°F is the cautious choice.

Threshold10%20%30%40%50%60%70%80%90%
36°FJun 10Jun 5Jun 3Jun 1May 29May 26May 23May 19May 15
32°FMay 30May 25May 20May 17May 14May 11May 8May 5Apr 30
28°FMay 14May 10May 6May 3Apr 30Apr 28Apr 26Apr 23Apr 19
24°FApr 29Apr 26Apr 23Apr 20Apr 18Apr 16Apr 13Apr 9Apr 6
20°FApr 19Apr 16Apr 12Apr 10Apr 7Apr 5Apr 4Apr 2Mar 31
16°FApr 11Apr 7Apr 5Apr 3Apr 2Mar 31Mar 29Mar 25Mar 20

First freeze in fall

The chance of an earlier freeze than the date shown. At 10 percent, one fall in ten freezes before the date.

Threshold10%20%30%40%50%60%70%80%90%
36°FSep 5Sep 9Sep 12Sep 15Sep 18Sep 21Sep 24Sep 27Oct 1
32°FSep 15Sep 20Sep 23Sep 26Sep 30Oct 1Oct 4Oct 7Oct 11
28°FSep 29Oct 2Oct 5Oct 7Oct 10Oct 14Oct 17Oct 22Oct 28
24°FOct 7Oct 12Oct 17Oct 20Oct 24Oct 28Nov 1Nov 4Nov 9
20°FOct 21Oct 27Nov 1Nov 3Nov 6Nov 10Nov 14Nov 17Nov 21
16°FNov 4Nov 9Nov 12Nov 15Nov 18Nov 20Nov 23Nov 27Dec 1

Growing season length

Days between the last spring and first fall freeze at each threshold, with the chance of a season at least that long.

Threshold10%20%30%40%50%60%70%80%90%
36°F1291231191151111081039993
32°F154148144140135132128124117
28°F180173168164161158155150142
24°F208203198195190186181176169
20°F230224219215211207204199192
16°F247241236232228225221215209

How often it gets that cold

The share of years with at least one night at or below each temperature.

36°F or colder
100% of years
32°F or colder
100% of years
28°F or colder
100% of years
24°F or colder
100% of years
20°F or colder
100% of years
16°F or colder
100% of years

Degree days

A degree day is one degree of the daily mean temperature beyond a base, for one day. Heating degree days count cold (the fuel a house burns), cooling degree days heat, growing degree days the warmth a crop needs; each crop has its own base.

Heating degree days, base 65°F
8,404
Cooling degree days, base 65°F
224
Growing degree days, base 40°F
3,572
Growing degree days, base 45°F
2,623
Growing degree days, base 50°F
1,804
Growing degree days, base 55°F
1,115
Growing degree days, base 60°F
577

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,51400
February1,31600
March1,17202
April731123
May3788153
June13642360
July4492513
August7362454
September24819241
October594152
November90506
December1,29400

What this means

NOAA computes these from the daily lows at the station over 1991-2020, fitting the dates of each year's last and first freeze to a distribution, so a date can be stated at any level of risk. 36°F is a frost risk for tender plants on a clear, calm night, since the ground cools below the air above it; 32°F is a freeze; 28°F is a hard freeze that kills most annuals.

The station is 1.7 km from Berlin. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

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Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00270690 (Berlin). Public domain.